Gaseous detonation waves can propagate in and be influenced by various geometric configurations. In cylindrical rigid tubes, the propagation can be in the form of a multi-cellular detonation in large-diameter tubes, a spinning detonation in tubes of moderate diameter, and/or galloping detonation in tubes of very small diameter. In channels of rectangular cross sections of various aspect ratios, similar cellular or galloping modes can be also achieved. In between parallel plates, when the gap between the plates is much smaller than the plates' lateral span, a two-dimensional cellular detonation can be achieved because of suppression of transverse waves in the direction normal to the plates. Other configurations are those of detonations stabilized in supersonic flows, which can be relevant to the problem of detonative propulsion and detonation engines.
Detonation combustion is an efficient way to burn a mixture of fuel and air to release chemical energy. The theoretical efficiency of detonation combustion, which is calculated by dividing work output by heat input, is approximately 49%. By comparison, more traditional processes, such as constant volume combustion or constant pressure combustion, have theoretical efficiencies of 47% and 27%, respectively. The enhanced efficiency of detonation combustion is attributed to its unique heat release process, in which burning of the fuel-air mixture occurs tens of thousands of times faster than in conventional combustion, which relies on a propagating flame front. Although more efficient, detonation combustion can also be more difficult to control. For instance, difficulties arise when initiating and sustaining detonation combustion. However, recent advances in engine control technologies allow these difficulties to be overcome.